This often happens when I copy-paste the same mover.
I made a cubic room, no features, and a smaller room by it's side, so that they touch face-to-face.
I made the simplest mover:
Cube->add->texture->intersect->select dx mover from classes->make mover.
Placed it inside the smaller room. Everything worked as expected.
However, if I copy and paste said room with a mover anywhere on the map, some copies/original will simply disappear, while some will look like they have a copy of themselves stacked below them, through you can walk through that stacked one.
Clearly looks like a BSP error but why does it happen and how do I avoid it?
UnrealEd 1. I'd rather try and find any possible solution for UED1 before switching to UED2, because I like it more.